A reactor core for use in a chemical reactor includes first and second reactor core sections. Under normal operating conditions, R-LEDs are driven by the battery voltage, but G- and B-LEDs are driven by the step-up voltage. The upper evaporating chamber contains a series of refrigerant pockets interleaved vertically with the vapor chambers to increase the surface area for heat transfer between the refrigerant vapor and the second refrigerant for absorbing heat by the second refrigerant for liquid-to-vapor transformation.